Exit to userspace with an emulation error if KVM encounters an injected
exception with invalid guest state, in addition to the existing check of
bailing if there's a pending exception (KVM doesn't support emulating
exceptions except when emulating real mode via vm86).
In theory, KVM should never get to such a situation as KVM is supposed to
exit to userspace before injecting an exception with invalid guest state.
But in practice, userspace can intervene and manually inject an exception
and/or stuff registers to force invalid guest state while a previously
injected exception is awaiting reinjection.
Fixes: fc4fad79fc3d ("KVM: VMX: Reject KVM_RUN if emulation is required with pending exception")
Reported-by: [email protected]
Signed-off-by: Sean Christopherson <[email protected]>
---
arch/x86/kvm/vmx/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index cf8581978bce..c41f0ac700c7 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -5465,7 +5465,7 @@ static bool vmx_emulation_required_with_pending_exception(struct kvm_vcpu *vcpu)
struct vcpu_vmx *vmx = to_vmx(vcpu);
return vmx->emulation_required && !vmx->rmode.vm86_active &&
- vcpu->arch.exception.pending;
+ (vcpu->arch.exception.pending || vcpu->arch.exception.injected);
}
static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
base-commit: 84e5ffd045f33e4fa32370135436d987478d0bf7
--
2.36.0.464.gb9c8b46e94-goog
On 5/3/22 00:18, Sean Christopherson wrote:
> Exit to userspace with an emulation error if KVM encounters an injected
> exception with invalid guest state, in addition to the existing check of
> bailing if there's a pending exception (KVM doesn't support emulating
> exceptions except when emulating real mode via vm86).
>
> In theory, KVM should never get to such a situation as KVM is supposed to
> exit to userspace before injecting an exception with invalid guest state.
> But in practice, userspace can intervene and manually inject an exception
> and/or stuff registers to force invalid guest state while a previously
> injected exception is awaiting reinjection.
>
> Fixes: fc4fad79fc3d ("KVM: VMX: Reject KVM_RUN if emulation is required with pending exception")
> Reported-by: [email protected]
> Signed-off-by: Sean Christopherson <[email protected]>
> ---
> arch/x86/kvm/vmx/vmx.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
> index cf8581978bce..c41f0ac700c7 100644
> --- a/arch/x86/kvm/vmx/vmx.c
> +++ b/arch/x86/kvm/vmx/vmx.c
> @@ -5465,7 +5465,7 @@ static bool vmx_emulation_required_with_pending_exception(struct kvm_vcpu *vcpu)
> struct vcpu_vmx *vmx = to_vmx(vcpu);
>
> return vmx->emulation_required && !vmx->rmode.vm86_active &&
> - vcpu->arch.exception.pending;
> + (vcpu->arch.exception.pending || vcpu->arch.exception.injected);
> }
>
> static int handle_invalid_guest_state(struct kvm_vcpu *vcpu)
>
> base-commit: 84e5ffd045f33e4fa32370135436d987478d0bf7
Queued, thanks.
Paolo